Another complicating factor, accentuated by the PLoS ONE study, is that chemical environments under which any particular clay can emerge can greatly influence its toxicity, adsorptive qualities and, according to their findings, its antibacterial effects.
"Because natural mineral mixtures can be variable, both mineralogically and chemically, we must continue to define specific chemical properties that influence the antibacterial effectiveness," Haydel said. "Our goal is to understand the details, so we can, in the future, perhaps generate mineral mixtures that mimic the chemical compositions and environment, so that the antibacterial activity can be controlled and ensured."
This work is about eliminating the unknowns," Koehl said. "We have more analysis to do, looking at the leachate composition, the action of the chelators and activity of the iron scavengers."
Koehl, who is working with Haydel as part of the School of Life Sciences Undergraduate Research (SOLUR) program, said of her experience: "Science is like an obstacle course. I've learned that when you come across problems in the laboratory, you have to be creative to work them out. This process has helped me be more critical, to be a thinking scientist, because I've had to analyze my own experiments and figure them out. This isn't just something that someone handed to me on paper in a classroom."
Studies are moving forward in other laboratories to develop structured clays for slow-release topical medical treatments, but there may be chemical schemes that come from Haydel's research, supported by the National Institutes of Health, that enhance their effectiveness.
"This study has given me an idea of how things move from idea to shelf," Koehl said. "One day, when I am a pharmacist, maybe I'll be selling this!"
|Contact: Margaret Coulombe|
Arizona State University